Title

Author

Date of Award

2011

Document Type

Open Access Thesis

Department

Civil and Environmental Engineering

First Advisor

Charles Pierce

Abstract

When a particular soil from a borrow pit is being used to construct a road embankment, it is important that the strength and erodibility characteristics are known to ensure the embankment has sufficient load capacity and is resistant to erosion by rain or flooding. To evaluate the borrow pit material’s strength and erodibility characteristics, forty five-gallon buckets of soils were collected from fourteen borrow pits in South Carolina. Three buckets were collected at three different locations within each pit.

Fifteen sets of direct shear tests were performed on the selected fifteen buckets of soils. There are six buckets of soils from the upstate area, six buckets from the fall zone, and three buckets from the coastal area. They are all typical soils from each area. All of the specimens were remolded to 95% of the maximum dry density with moisture content between -1% to +2% of the optimum moisture content. Based on the results, soils from D2-Anderson-01, B-1 (MH), D2-Abbeville-01, B-1 (SM), D4-York-04, B-2 (SM), D2- Abbeville-01, B-3 (SM), D1-Richland-08, B-2 (ML) and D1-Richland-08, B-1 (ML) are acceptable for embankment construction usage. That is, they have high effective friction angles, which fall in the range specified by the South Carolina Department of Transportation (SCDOT) Geotechnical Design Manual 2008.

Nineteen pinhole tests were performed on all the soils which were suitable to run this test to evaluate the erodibility of the borrow pit soils. Based on the results, most of the soils were non-dispersive soils when compacted to 95% of the maximum dry density with moisture content between -1% to +2% of the optimum moisture content. Soils from D2- Abbeville-01, B-1 (SM), D1-Lexington-05, B-3 (SC), D6-Berkeley-01, B-2 (SM), D3- Oconee-01, B-3 (CH) and D1-Richland-08, B-3 (CL-ML) are slightly dispersive soils, thus caution should be taken when they are used in embankment construction. For these cases, erosion control mats, retaining structure or specially designed filters may be needed to prevent erosion failure of the embankment.